<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        const promise1=new Promise((resolve,reject)=>{
            console.log('promise1')
            resolve('resolve') //立刻 第一个宏任务 pending->fullfilled
        })
        // promise1.then 的返回值还是promise
        const promise2=promise1.then((res)=>{
            console.log(res)
            return new Promise((resolve,reject)=>{
                // setTimeout(resolve,2000)
                resolve(111)
                console.log(promise2,'---');
            })
        })
        console.log(promise2,'------');
        console.log(1,promise1);//1 Promise{<fullfilled>}
        console.log(2,promise2);//2 Promise{<pending>}
    </script>
</body>
</html>